Like this:

“but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die”. -Genesis 2:17

This certainly sounds like a punishment for disobedience. And disobedience is a sin. Death came into this world through sin; and who sinned here is the first man and woman whom god created in his own image. God said “for when you eat from it you will certainly die“, death was not designed as part of human life until Adam and Eve sinned.
Now that sin entered the world and as a result death into our lives, what happens to a person after death is still a mystery. But Bible compares death to sleep.

“For the living know that they will die, but the dead know nothing; they have no further reward, and even their name is forgotten. Their love, their hate and their jealousy have long since vanished; never again will they have a part in anything that happens under the sun”. -Ecclesiastes 9:5

Did God create us only to see us die? No. God does not want us to be lost in death forever. Rather, he wants us to spend our life eternally in his kingdom- which is the actual purpose of creating us. We have hope that death is not the end of our existence, we have an immortal life to live. The way to such a life is Jesus Christ and the good news is he has already did his part on the cross so that we can victoriously raise from death.

“Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned”. -Romans 5:12

One man brought sin into this world for all the mankind and God by his grace sacrificed his only son as a penalty for each individual’s sin in order to reconcile the relationship between man and God that was long lost in Eden. This explains the reason why Jesus Christ was born on earth. So that by his blood we be clean.

“For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.” -John 3:16

Is death really a curse?

Well, It might appear as one but it actually is surrendering the soul back to the God who gave it and resting in the grave until Jesus Christ calls us in his second coming.

“and the dust returns to the ground it came from, and the spirit returns to God who gave it.” -Ecclesiastes 12:7

But why die? This is because we cannot enter God’s kingdom with this sinful body, there needs to be a transformation both in heart and body. By receiving Jesus Christ as our savior we can assure a place in his family and by losing this body in death we lose our earthly self.

“I declare to you, brothers and sisters, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable.” -1 Corinthians 15:50

It is the effort made by God to restore the glory that mankind lost because of sin. The kind of life that we live now and death are just different stages of the whole process, in a way to enter his kingdom. Never forget the fact that we will all be resurrected to immortal life someday.